Panel and method of making



April l1, 1939.

J. J. WHELAN PANEL AND METHOD OF MAKING Original Filed Aug. 23, 1937 Patented Apr. 11, 1939 UNITED sTATEs PANEL AND METHOD OF MAKING John J. Whelan. Washington, D. C., assigner to Copper Houses, Inc., New York, N. Y., a corporation of Maryland Application August 23, 1937, Serial No.

Renewed February 28, 1939 mates 7 claim. (ol. r2li- 91) This invention relates to a panel and method of making and more particularly to a method of securing a thin covering of metal, such as copper, to a rigid base. such as wood or other ilbrous '5 board, and the product resulting from the method.

Anobject of the invention is to provide a panel in'which a thin -layer of metal is secured to a relatively rigid base structure. n t

.- t Another object of the invention is to provide a metal covered brous panel which may be made in relatively large sizes and upon which a thin metal covering is rrnly secured.

Another object of` the invention is to provide ,15 a panel having a thinf metal covering secured thereto and maintained under tension.

Another object of the invention is to provide a panel having a, metal covering thereon which is not impaired by temperature changes to which the panel is subjected during use.

Another object of the invention is to provide A an improved process of securing a metal covering to a b'rous panel base.

A further object of the invention is to provide a method of securing a thin metal covering to a rigid panel base such that the metal is under tension in the resulting product.

A still further object of the invention is to provide'a process of adhesively securing a thin 30 metal covering to a panel base so that the bond between the metaland `base is not affected by changes in temperature.

Other objects and advantages of the invention will appear in the following description of preferred embodiments of the invention and the attached drawing of which:

Figure 1 is a perspective end' view of a portion of a, panel of the present invention;

Figure 2 is a fragmentary end view of the panel of Figure 1 upon an enlarged scale; and

lFigure 3 is a view similar to Figure 2 showing a modified structure.

'I'he panel of Figures 1 and 2 includes a base member I0 which may be of any relatively rigid ,45 material, for example, stili brous wall board or wood, the preferredmaterial being plywood. A layer of thin metal Il completely covers one face oi the base member I0 and is folded around the edges I2 of the base so that portions I3 of the ,60 metal layer completely cover the edges of the base and portions I4 extend a short distance over the opposite face of the base member, as shown in Figure 1. A layer of adhesive I5, preferably a thermoplastic adhesive, such as asphalt, is provided between the metal and the base member so as to adhesively secure the metal to the base member.

The metal layer Il is maintained under tension upon the base member I0 by securing the metal to the basemember while the metal is heated above the highest temperature to whichit will be subjected to in use. During application, the thermoplastic adhesive is in plastic or molten condition so that itfbonds the metal to the base member upon cooling. Also, the portions I3 and lo I4 of the metal layer are formed around the edges I2 of the base member while the metal is in heated condition so that upon cooling the contraction of the metal places the same under tension and stretches the metal to form a smooth metallic surface. y

Panels of the present invention are particularly adapted for external use in building structures, although they may. of course, be employed for forming an internal surface of a building struc- 20 ture or for other purposes. The metal preferably employed is copper although other similar ductile metals, such as zinc, having resistance to corrosion upon weathering, may be employed. It has been found that a layer of copper exposed to` 25 sunlight will reach a temperature approximately 40 F. above air temperature. Ordinarily air temperatures do not rise substantially above F. and the highest temperature reached by copper exposed to the sun is approximately F. Thus, by heating the copper somewhat above 140 F. and securing the same to a panel by an adhesive and folding the metal around the edges o1' the panel, the copper will be placed under tension and the temperatures reached in use 35 will not release this tension. It is important that the metal be not heated to an excessive temperature during application as the resultant strains during cooling may cause rupture of a tin metal layer and also the excessive tension produced 40 may tend to warp the base member. It is also desirable that the thermoplastic adhesive employed should be somewhat softer at theA highest temperature reached in use so as to yield slightly and equalize any local stresses set up by tempera- 45 ture changes of the panel ywhen positioned upon a `building structure. l

`A preferred adhesive is an asphalt having a melting point somewhatabove 140 F. but below 200 F. so that the adhesive will be completely 50 molten at 200 F. Such an asphalt will tend to become slightly plastic at temperatures in the neighborhood of 140 F. Also it is rpreferred to heat the copper to a temperature of approxitemperature has been found to maintain the copper in tension under any temperatures to which it is subjected during use and also to be low enough such that warping of the entire panel does not take place.

A preferred method of making the panel of Figures 1 and 2 is to pass the base member III between rolls and feed sheet metal simultaneously through the rolls so that the metal is pressed against the surface of the base member. Molten asphalt at a temperature at least as high as 200 F. is continuously fed between the metal and base member and distributed upon the surfacestlereof so as to impart its heat to the thin metal sheet to heat the same to a temperature between approximately 180 and 200 F. 'I'he roll in contact with the metal sheet may also be heated to assist in imparting the desired temperature to the metal. A metal sheet somewhat wider than the base member is employed so that excess material along the edges of the sheet is provided for folding around the edges of the base member. This folding is preferably accomplished by passing. the base member continuously from the first mentioned rolls through forming rolls for bending the metal sheet around the edges of the base member. Additional adhesive may be distributed upon the edge and a portion of the opposite face of the base member immediately before the composite panel enters the forming rolls or suillcient asphalt may be delivered and distributed upon thepanel before it enters the first mentioned rolls. The forming rolls may also be heated in order to maintain the temperature of the copper during the forming operation.

The panel may also be produced by placing the sheet of metal and base member with an intermediate layer of adhesive in `a press and pressing the metal and base member together while the metal is in a heated condition. The edges of the Y metal sheet may be folded about the edges of the base member while the metal is still in a heated condition either --in` the same pressing operation or a subsequent operation. The portions of the press in contact with the metal may be heated in order to impart the desired temperature to the metal sheet and adhesive or a heated adhesive may be employed.

After the panel is formed it is then cooled and this cooling causes the metal to contract so as to produce the tension above referred to. The adhesive hardens during the cooling but remains suiilciently plastic during the first part of the cooling to allow the tension of the metal to be substantially uniformly distributed throughout the face portion of the panel.

By applying metal to a wood or other base in this manner, extremely thin metal may be employed. For example, copper or other metal sheets ranging from three thousandths to fifteen thousandths in thickness may be satisfactorily employed, depending upon the use of the panel. The' tension to which the metal is subjected stretches the same and gives the appearance of a sheet of metal of considerable thickness. The

relatively rigid fibrous base, such as wood or berboard, has sulcient resiliency that impacts against the metal surface.are largely absorbed by the base member such that material is not easily ruptured. If corrosion resistant metal such as copper is employed ordinary weather conditions do not affect the panel over extended periods of time and the backing such as plywood is protected.

'Ihe structure shown in Figure 3 is essentially similar to that of Figures 1 and 2 and differs only, in that, a layer of resilient material I8 is positioned between the metal layer` AI3 and the base member I0. The resilient material I6 may be of paper, thin felt, or any other sheet fibrous material which is less rigid than the base member I0. Avpreferred material is a relatively heavy paper which has been crinkled substantially in the same manner as crepe paper and saturated with a saturant such as asphalt. The paper I0 is adhered to the base member III by a layer I1 of adhesive, preferably the same type of thermoplastic asphalt described with reference to Figures l and 2. The metal sheet I3 is likewise adhered to the paper I6 by a layer I8 of adhesive, also preferably the thermoplastic asphalt above described. 'I'he layer of paper IB is preferably of l sufficient area to extend under the edge portions I3 and Il of the metal but if desired may cover only the face of the base member. This layer of resilient material I6 is effective to further take up strains due to differences in coemcient of expansion in the base member and the metal. It also acts as a cushion to prevent rupture of the metal due to abrasion or impact thereon.

The structure of Figure 3 may be produced in substantially the same manner as that of Figures l and 2. For example, the base member, resilient layer I6 and metal sheet I0, may all be fed simultaneously to the same set of rolls along with heated asphalt so that the asphalt is deliveredboth between the metal I3 and the paper I6 and between the paper I6 and base member I0. Alternatively, the paper I6 may be first adhered to the base member I0 by a rolling operation in which adhesive is delivered between the layer I6 and the base member III and then the metal layer subsequently applied in the same manner as described With reference to Figures 1 and 2. In either case, the metal layer is folded around the edges of the base member I0 so that-the metal is placed under tension upon cooling after the rolling operation.

While I have described preferred embodiments of my invention, it is understood that the details thereof may be varied within the scope of the following claims.

What I claim is:

1. In a panel structure, the combination of, a rigid base member, a relatively thin layer of metal adhesively secured thereto, said metal being secured to the edges of saidbase member and being under tension, whereby said thin layer of metal is maintained in a smooth condition when exposed to the sun.

2. In av panel structure, the combination of, a rigid base member, a relatively thin layer of metal covering at least one face of said base member, a layer of thermoplastic adhesive between said base member and said metal for securing the metal to said base member, said metal layer being folded about the edges of said base member and being stretched across the face of said base member, whereby said thin layer of metal is maintained in a smooth condition when exposed to the sun.

3. A panel structure adapted tc be used upon the exterior of building structures, said panel comprising a rigid fibrous base member, a relatively thin layer of corrosion resistant metal covering at least one face of said base member, a layer of thermoplastic cement having a melting point above the temperature which the layer 4of metal will reach when exposed to the sun, said metal layer being stretched across the face of said base member and retained thereon under said layer to completelyvlose saidtension.

4. In a panel structure. a rigidv nbrous base i member, a relatively thin layer of metal covering a face of said base member and stretched between the edges thereof, the tensioncaused by the stretchingof said metal -being sumcient to produce a substantially smooth surface and to maintain such surface when exposed `to the sun `but being insufiicientto cause substantial warping of said base member.

- 5. In a panel structure, the combination of, a rigid base member, a layer of relatively thin sheet metal covering a face of said basemember, a layer of iibrous material between said metal and said base member and adhesively secured to both said metal and base member, said metal being secured to the edges of said base member and stretched between said edges so as to be main- .zo tained under tension. whereby said thin layer of metal is maintained in a smooth condition when ing a rigid base member and a covering of relatively thin sheet metaLsaid method comprising,

' pressing said sheet against a face of said base member in the presence of a thermoplastic s'tdand expand the same, folding the edges of said sheet about the edges of said base member whileA said sheet metal is in heated condition and theref after cooling said sheet metal to stretch the same across the face of said base member.

'7. T he process lof making a panel member. which comprises, applying a layer of thermoplastic adhesive material to a face oi a base mem- `ber, superlmposing a thin sheet of metal in heated condition upon said layer of adhesive material, applying pressure to said thin sheet of metal to unite the same with said rigid base member, tightly securing said sheet of thin metal to the edges of said base member; and thereafter allowing said sheet of metal to cool to thereby stretch said metal across the face of said base member.

JOHN J. WHELAN. 

